I found a star called "Theblackknight13". Planet I was class 18. Or so I thought. After colonizing turns out it was class 8. The name popup said "Theblacknight 13 I8", which looks like "18" in the current font. "Theblacknight13 II" and longer names get smooshed with the planet class.
So, either the star name is too long, or the popup needs to expand to avoid confusion.